I have a copper drinking cup and a corn boiler that are tinned. My wife recently purchased a kidney canteen for me that is not tinned. Is there any reason for the difference? I thought tinned utensils were safer to use. Then I started to think-"water lines in houses are untinned copper tubing". Can anybody enlighten me?

When one cooks acidic food, or stores acidic food, in copper or brass vessels, the acid can react over time, and produce verdigris, a very toxic substance. Luckily, it is also green in color, sometimes bright green, and so is easily seen so you may clean it off. Tinning of brass or copper eliminates the need for heavy scrubbing of the copper for the rust that forms on tin is not toxic per se. FYI apple butter and beer are both cooked or brewed in unlined copper vessels..., both are acidic, but the consumers are not made ill, for the vessels are kept very clean. Recently, say in the past few decades, the acid-food-in-copper-warning has digressed in rumor to be "it's unsafe to cook in untinned copper vessels", which is very inaccurate.

Now as for pipes..., unless the water is very soft, the hardness of the water due to minerals, deposits itself on the inside of the pipes as "scale", and this forms a barrier that prevents any contamination by corrosion of the copper. In Ancient Rome, pipes were made of very soft lead, but the water is hard, so scale prevented lead poisoning of the general population. BUT..., they also used lead or a very lead laden pewter to line the vessels used to heat wine (a popular method of consuming it), and when you have heated foods or drinks that come into direct contact with lead..., you get lots of lead into the food, and then into the people who consume it..., so rich folks like Imperial Roman Nobility, probably poisoned themselves to a great degree. Kinda explains Nero, and the rest eh?

LD

_________________It's not what you think you know; It's what you can prove

Well first, is it a tea pot, or tea kettle? I ask as you boil the water alone in the kettle, and brew the tea in a pot. I would not brew the actual tea in a copper vessel to avoid lots of cleaning.

You can use vinegar and salt, followed by a good rinse and then drying to clean copper or brass. It will shine but soon brown. There are lots of copper cleaners on the market that are acceptable. One could use Soft Scrub as well as the abrasive in it is chalk.

I know Peter Goebel well, and he and I discussed the tinning issue years ago. He tins much more than he needs to, because his customers are usually aware of the copper and food rumor, so they won't buy without it.
I have a brass trade kettle, unlined, and no worries so far.

I know that tomatoes have atropine in the leaves of the plant, which most folks think led to the idea that all parts of the tomato plant, fruit included, were bad, and one name for them was Wolf Apple. I wonder if folks who tried cooking the fruit might have used copper, and let the stuff sit in the kettle too long, got violently ill, and thus decided them bad?

LD

_________________It's not what you think you know; It's what you can prove

I know that tomatoes have atropine in the leaves of the plant, which most folks think led to the idea that all parts of the tomato plant, fruit included, were bad, and one name for them was Wolf Apple. I wonder if folks who tried cooking the fruit might have used copper, and let the stuff sit in the kettle too long, got violently ill, and thus decided them bad?

LD

Tomatoes are acidic and will leach the copper out if left to sit. Too much copper is toxic even though a little is necessary in our diet.